FR2705618A1 - Sealing ring between the beads of a tire for handling equipment. - Google Patents

Abstract

Annular element (3) placed between the two beads (12) of a tire P mounted on a rim J with a flat bottom. In order to be able to use said tire P on said rim J, without the provision of an air chamber, the annular element (3) in order to ensure the tightness of the assembly has a contour in meridian section, and in particular two lateral sides (30) such as the clamping s, between the ring (3) and the beads (12), zero or even negative at the base of the ring (3), then grow weakly over a certain distance radial h1, then strongly over a distance h2 radially adjacent to the first.

Description

4 2705618

  The present invention relates to an annular element intended to be placed between the two beads of a tire without an inner tube, mounted on a rim with a flat base and one of the flanges of which is removable; said tire being particularly intended to equip handling machines. It also concerns

  the assembly formed by the ring, the tire and the rim.

  The usual tires for handling machines, as in almost all cases where the tires are mounted on flat rims, are tires vulcanized using vulcanization membranes, called "honeycomb" membranes and as described by example in US Patent 3,970,416, and used with an air chamber and a protective element of small thickness and placed between said chamber and the rim tape. This annular element most often has axial ends or lips of suitable shape so as not to

  injure the inflation air chamber.

  In most cases, tires for handling machines have an internal H / B shape ratio at most equal to 0.8 and often close to 0.5, H being the height of the internal cavity of the tire measured between the bottom of rim and the point of the interior wall of the cavity furthest from the axis of rotation of the tire and B being the maximum axial width of the interior cavity. It follows that numerous damages appear on the air chambers necessary for the running of such tires, in particular rapid wear.

bedrooms.

  Furthermore, the tires studied are generally mounted on flat rims formed of three elements which are the rim tape secured to a first rim flange, the locking ring, and the second rim flange. When the rim is intended for use with a tubeless tire, it is possible to mount such a tire on such a rim, a seal being generally provided between the bead of the tire and the rim on the side of the removable rim flange . However, the fact that the dimensional characteristics of the rims have fairly wide tolerances, that these rims are often deformed and messy, that the difficulties in placing and maintaining a seal in the correct position are numerous, does not allow obtaining a correct seal when fitting a tire without

  chamber on a flat rim or a similar rim with three elements.

  In order to obtain the seal of a tire without an inner tube mounted on a rim of the kind described, the invention uses, for mounting said tire on said rim, a sealing ring placed on the rim strip included between the two. tire beads. This ring is characterized in that its meridian section, in the free state, is delimited by a radially inner generator of radius equal to the radius of the rim portion on which it will be placed and of axial width between 0.8 and 1 times the axial distance separating the axially inner ends of the bead tips, by a radially outer generator of radius greater than the radius of the inner generator by an amount hc of between 0.05 Rj and 0.40 Rj, Rj being the radius at seat of the wheel, and by two lateral sides of identical profiles such as the transverse tightening of the ring on the internal walls of the beads, negative or zero at the level of the internal generator, either successively, slightly increasing over a radial distance hl to less equal to 0.05 Rj, then strongly increasing over a radial distance h2au more equal to 0.4 Rj to become at most constant over the radial distance h3 at least equal to 0.02 Rj, and which, added to the heights h1

  and h2, represents the height hB of the lateral sides of the ring, the difference hB -

hC at most equal to 0.05 Rj.

  The transverse tightening of the sealing ring on the axially inner walls of the beads, on a generator of given radius relative to the axis of rotation, means the difference, at this generator, between the axial width of ring not mounted and the axial distance separating the two beads of the tire mounted on its service rim and inflated to its nominal pressure. If s is called transverse tightening, LA the axial width of the ring

  and LB the axial distance between the beads, s = LA - LB.

  I1 should be understood by low growth of the tightening over the distance h1 a uniform, continuous and substantially linear growth until obtaining, at the level of the generator located at the radial distance h1 from the rim tape, a maximum of

  positive tightening and preferably at most equal to 0.3 LA.

  A strong increase in the tightening over the non-zero distance h2 is a uniform, continuous and substantially linear growth until obtaining at the level of the generator radially distant from the rim tape the distance hl + h2 a

  maximum positive, linear tightening and preferably at least equal to 0.15 LA.

  Strong growth over the non-zero distance is infinite growth up to

  a tightening value at least equal to 0.15 LA.

  By more constant tightening, we mean constant tightening or decreasing tightening, with the radial distance measured from the rim tape, while

remaining positive.

  The distance hl will advantageously be between 0.05 Rj and 0.20 Rj, and over a radial distance at most equal to 0.5 hi, the tightening LA-LB will be advantageously negative, the width of the ring being smaller than the axial distance separating the two beads, which makes it easier to mount the ring pneumatic assembly on the service rim. The radial distance h2 will advantageously be between 0 and 0, 1 Rj, which gives a strong growth of tightening over a small height interval and thus allows a better grip.

  seal at the lips of the seal ring.

  As for the distance h3, it will advantageously be between 0.02 Rj and 0.1 Rj. The growth sequence thus described allows better deformation of the lips of the sealing ring, due to their shapes, and thus increased efficiency from the sealing point of view. The shape of the meridian section of the ring allows the appearance, at the optimal location, of the pressure force of the lips of the ring on the beads necessary for sealing, without necessity

  to have a circumferential tension constraint of said ring mounted on rim.

  In order to obtain very easy mounting of the ring and of the tire, the Shore A hardness of the material constituting it will preferably not be greater than 65, the Shore A hardness being measured according to standard ASTM D67549T. The use of such a property is advantageously possible given the claimed shape of the ring according to the invention which, as known, for example in application FR 2 246 409, has the same advantages as the rings of the art front, and in particular that of holding the beads of the tire in place, when

  it rolls under very little or no pressure.

  Another non-negligible advantage of the ring according to the invention is its simplicity of construction and consequently the low cost: it in fact requires no reinforcement to keep it pressed against the rim tape. Due to the extensibility and the extension of the lips of the ring, it appears a tightening on the rim tape sufficient for good support and centering

of the ring.

  The characteristics and advantages of the invention will be better understood using

  the description which follows and which refers to the drawing, illustrating without limitation the

  examples of execution and in which - FIG. 1 schematically represents a non-deformed ring inside the tire of dimension 180/70 R8 XZA mounted on the service rim

4.33 / 8,

  - Figure 2 also shows the meridian section of a sealing ring according to the invention, - Figure 3 similarly shows a variant of the sealing ring, - Figure 4 likewise shows the ring according to the invention as it stands

  deformed inside the mounted tire and inflated to its nominal pressure.

  The ring (3) according to the invention is used with a tire P. referred to above, for handling equipment. The tire P comprises a tread (11) joined, by means of two sidewalls (10) with two beads (12), each reinforced by a bead wire (14) (FIG. 4) around which the anchor is anchored. 'carcass reinforcement (13) by forming reversals (13'). This tire P, with an internal shape ratio H / S equal to 0.7, is mounted on a rim J, comprising a flat rim bottom (20) secured to a fixed rim flange (21), and joined to a removable rim flange (22) via a ring

lock (23).

  In these rim configurations, the radius at the rim seat Rj is the radius of the rim tape. The sealing ring (3), shown in FIG. 1 inside the tire P mounted on the rim J and in the non-deformed state, is shown in detail in FIG. 2. The meridian section of the ring 3 is delimited radially on the inside by a generator (31) parallel to the fax machine for rotating the rim (J) for mounting, and of radius RA equal to 101.6 mm and to the nominal radius Rj of the rim tape (20) , and radially to the outside by a non-rectilinear generator (32), so that the radial distance hC separating said generators and measured on the axis of symmetry XX 'of the meridian section is less than the radial distance hB separating the same generators and measured on a parallel to the axis of symmetry XX 'passing through the end of the axially farthest section from said axis of

  symmetry. In the case studied and shown, hC is 0.17 Rj and hB is 0.18 Rj.

  Laterally, the meridian section of the ring (3) is delimited by two sides (30) symmetrical with respect to the axis XX 'and formed respectively starting from the

  generator (31) of the line segments (33), (34) and (35).

  If we consider a generator G parallel to the generator (31) and radially distant from said generator (31) by the distance h variable between a zero value and the value hB, this generator G has with the two lateral sides (30) intersection points A axially distant from the distance LA, and with the inner walls of the beads (12) intersection points B axially distant from the distance LB. The distance LA-LB is the tightening s of the ring on

the beads (12).

  As shown in Figure 2, when the distance h is zero, the generator G is none other than the generator (31) and the tightening s is then negative, the axial distance LAO, which is the width of the generator (31) , being less than the axial distance LBO separating the two axially inner ends of the tips (15) of the beads (12). On the radial distance hi, equal to 0.1 Rj and corresponding to the segments (33), the tightening LA - LB is slightly increasing, passing from a negative value to a positive value at the level of the height ho equal to 0, 05 Rj and increasing to the level of the height hl and equal to 0.13 LA. On the radial distance h2, equal to 0.02 Rj and corresponding to the segments (34), the tightening s is strongly increasing and it goes from the value 0.13 LA to a value 0.38 LA for the relatively short radial distance h . On the radial distance h3, the tightening s becomes decreasing, due to the curvature of the internal wall of the bead (12), while remaining positive to become at the level of the radial distance hB equal to

0.32 LA.

  3 shows a variant of the sealing panel (3) in which we can detect, compared to the sealing ring of Figure 2, the following differences. The width LAO of the generator (31) is equal to the axial distance LBO separating the axially inner ends of the tips (15) of the beads (12), the tightening is therefore zero. It then becomes positive and increases as in the case of FIG. 2 but the segment (33) of said figure is replaced by a first curvilinear arc (33), and the segment (34) by a second curvilinear arc (34), these two curvilinear arcs having extensions intersecting in O, located at the radial distance hl from the generator (31). The angular point in O can advantageously be replaced by an arc of a circle of short length and strong curvature, as shown on the lateral side of the ring situated on the left side of FIG. 3. The curvilinear arc (34) is extended radially outside by a line segment (35) substantially parallel in this example to the inner wall of the bead 12, along the distance h3, the values hi, h2, h3 of the

  Figure 3 being the same as those of Figure 2.

  FIG. 4 shows the assembly formed by the tire P. of the ring 3, and of the rim J, as it is assembled and after inflation by means of the bent valve extension V. The sealing ring (3), being lubricated on its inner cylindrical face and on its side walls, is placed inside the tire P. The tire-sealing ring assembly is then mounted on the rim J, and the assembly is inflated . The curvilinear segments or arcs (33) (34) are applied against the interior walls of the beads (12) by exerting a significantly higher contact pressure at the lips (40) of the ring 3 than at the segments or curvilinear arches (33), the lips (40) being constituted by the vulcanized rubber mixture portions making up the ring (3) and located between the generator (32) and the segments (35) and (34) on the lateral sides of the ring.

Claims (9)

  1. Sealing ring (3), intended to be mounted on a rim tape (20) and between the beads (12) of a tire P with an internal shape ratio H / B at most equal to 0.8, characterized in that, in the unassembled state, its meridian section is, delimited by a radially inner generator (31) of radius RA equal to the radius Rj of the rim tape (20) of the mounting rim J and of axial width LAO between 0.8 and 1 times the axial distance LBO separating the axially inner ends of the tips (15) of the beads (12), by a radially outer generator (32) of radius greater than the radius RA by an amount hC between 0.05 Rj and 0.40 Rj, and by two lateral sides (30) of identical profiles (33, 34, 35) such as the transverse clamping LA-LB of the ring (3) on the interior walls of the beads ( 12), negative or zero at the level of the interior generator (31), successively slightly increasing over a distance radial hl at least equal to 0.05 Rj, then strongly increasing over a radial distance h2 at most equal to 0.4 Rj to become at most constant over the radial distance h3 at least equal to 0.02 Rj, the sum of the distances hi, h2 and h3   being equal to the height hB of the lateral sides of the ring (1), the difference hB -   hC being at most equal to 0.05 Rj and the distances LA and LB being respectively the width of the ring (3) and the distance separating the beads (12), measured on   a generator G located at a variable radial distance h from the generator (31).   2. Sealing ring (3) according to claim 1, characterized in that the growth of the clamping over the radial distance hl is uniform, continuous and substantially linear until a clamping height hl is obtained.   maximum positive and at most equal to 0.30 LA.   3. Sealing ring (3) according to claim 2, characterized in that the growth of the clamping over the radial distance h2 is such that one obtains at the level   from the height h1 + h2 a maximum, positive tightening, at least equal to 0.15 LA.   4. Sealing ring (3) according to claim 3, characterized in that the   tightening on the radial distance h3 is positive and constant.   5. Sealing ring (3) according to one of claims 1 to 4, characterized in that   that the radial distance hl is between 0.05 Rj and 0.20 Rj.   6. Sealing ring (3) according to claim 5, characterized in that the   radial distance h2 is between 0 and 0.1 Rj.   7. Sealing ring (3) according to claim 6 characterized in that the   radial distance h3 is between 0.02 Rj and 0.1 Rj.   8. Sealing ring (3) according to one of claims 1 to 7, characterized in that   that it consists of a rubberized vulcanized mixture of Shore A hardness at plus 65 points.   9. Assembly comprising a tire P, a rim J, a ring (3) characterized   in that the ring (3) is a sealing ring according to one of claims 1 at 8.